Uneven pad wear

2001 175,000 mi.
Looking for experianced opinions.
My son is a trucker. My daughter in law rides along much of the time so car sets for a few months at a time. She came back so I gave the car a once over. When it came to brake inspection I found one inner pad severely worn. All other pads 80 percent left. Before dissassemble I made sure pins and slides moved freely and they did. Position moves freely everywhere. I was the last one to do these brakes so I know they were done right. The lube was still good on the pins and clips. I am puzzled on the cause. I did notice the rotor was in poor condition on the worn pads side. There was still some pad left. My first thought was that the last time I replaced rotors I might have used cheapies and the rotors pitted and wore the one pad. But that doesn’t sound right. The only other explanation I can come up with is that the brake hose is faulty and I couldn’t identify it because I moved the hose and that may have freed the plug. So I’m going to replace the pads, rotors, hose and slide pins and flush the fluid and call it good. My question is: is there something I’m missing. I have no absolute reason for this to happen.

How many pistons in the caliper?

One piston.

I am going with a bad hose. Not really bad, just bad enough to drag just that caliper a little bit more.

Unless that one pad had a bad mix of brake fricton material, I’d say it is the hose.

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My wag is the rotors.

Could be the culprit, the rotors are not in great condition, imhop

With that much pitting the pads will not wear evenly. What are the pad measurements in millimeters?

BTW, on vehicles less than 3 years old I have seen a wear difference of up to 3 mm, the inboard pad is usually hotter in extreme conditions.

Inboard 2.5 mm. Outboard 7 mm

That’s a cheap rotor that ground down the inner brake pad.


My guess is a little pitting in the caliper bore or tha square sectionof the O-ring is not doing it’s job in retracting the piston slightly. Now you have different opinions that cover all possibilities.

I thought of one other possibility, when I used to commute back and forth for work and sometimes park on the street in our high salt area, I sometimes got wear like that on the drivers side while the passenger side was fine.

The drivers side gets much more salt thrown at is from cars and salt trucks going the other way.

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That’s a good point if you park near the street, but in my experianced the left side of the car deteriates quicker because of the crown of the roads drains the salt to the left creating heavier concentrations and salt puddles on the cars left. That is unless your parking in town and getting pelted like you say.
At any rate I’m going to replace everything except the caliper. It just looks and acts too well to warrent replacement on this 20 year old car. If it happens again I’ll know I should have replaced it as well. It’s just frustrating to me not to be able to pinpoint the specific cause. But I’m sure :crazy_face: that the cause was remedied after I replace these parts. Thanks for the input.

Had the brakes done, second set at 165k miles. About 180k inside showing more wear than outer, mechanic bud greased up caliper pins?, not sure how that worked as it was totaled at 197k miles. I don’t know how many shops would say lets try lubing the caliper pins.

Caliper pins are always lubed. I clean and relube them on every brake job. If they are not lubed, that’s when they stick and cause uneven pad wear. On this vehicle the pins were sliding good, but for little money, I might as well replace them as I didn’t pinpoint the issue.`

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try changing the brake fluid and the hoses. maybe the one is stuck and is continuously braking

So I’m going to replace the pads, rotors, hose and slide pins and flush the fluid and call it good.

I’ve had the same thing happen. I chalked it up to my driving habits, perhaps habitually braking while turning at the same time. I never noticed it on that car again, perhaps because seeing it that one time taught me to separate turning and braking better than I had been.

Brake pads are cheap, so I’d just change them out and forget about it until the next brake job is due.

If there was a bad hose, which kept pressure on the caliper, wouldn’t that cause both pads to wear as they normally would?